Refrigerator latch



Dec. 27, 1955 G. E. CURTISS, JR., ETAL 2,728,596

REFRIGERATOR LATCH 3 Sheets-Sheet l Filed Nov. 8, 1951 s M 5./ m ww TW um c o @V EB EG. ,W G Rw ou Gm Dec. 27, 1955 G. E. CURTISS, JR., ETAL 2,728,596

REFRIGERATOR LATCH 3 Sheets-Sheet 2 Filed Nov. 8, 1951 .m m mR/ m MUM a w MQ. uw E y 5 mw @L m Dec. 27, 1955 G. E. cuRTlss, JR, ETAL 2,728,596

REFRIGERATOR LATCH 5 Sheets-Sheet 3 Filed Nov. 8, 1951 40 A GEORGE E. CURT/ss, JR. Lou/s G. oRowsK/ l l 46 49 Snventors b/t (Ittomegs United States Patent() nnrmonnaron Laren George E. Curtiss, Jr., and Louis G. Bobrowski, New Britain, Conn., assignors to The Stanley Works, New Britain, Conn., a corporation of Connecticut Application November 8, 1951, Serial No. 255,394

2 Claims. (Cl. 292-332) The present invention relates to latches and, more particularly, to an improved construction for a latch mechanism of a type particularly adapted for use with refrigerator doors and the like.

It is an aim of the invention to provide a latch mechanism which will be particularly suitable for cabinet and refrigerator use in that it will be of simple and economical construction and afford many advantages from an operational standpoint. Included in this aim is the object of providing a latch which will have the characteristie of affording a long period of draw-in during the latching operation and which will provide a closing force during the draw-in in accordance with a predetermined performance curve. In this way the criticality of the positioning of the strike may be materially lessened and the attainment of an efhcient and effective latching and sealing of the door may be insured.

lt also is an object of the invention to provide a latch of the character described which will be of simple construction and of the type wherein the bolt may be manually retracted and upon retraction will be retained in retracted position, yet which will be automatically shifted to closing or latching position when the door is moved to tripping position.

Other objects will be in part obvious, and in part pointed out more in detail hereinafter.

The invention accordingly consists in the features of construction, combination of elements and arrangement of parts which will be exemplified in the construction hereafter set forth and the scope of the application of which will be indicated in the appended claims.

ln the drawings:

Fig. l is a top plan view of the latch mechanism incorporating the features of the present invention, the latch mechanism being associated with a refrigerator door and cabinet which are shown in fragmentary crosssectional View;

Fig. 2 is a side View of the latch with the frame cut away to show the moving parts and with the bolt in latched position;

Fig. 3 is a view similar to Fig. 2 with the bolt in unlatched or open position;

Fig. 4 is an end view of the latch mechanism;

Fig. 5 is a cross-sectional view taken along the line 5 5 of Fig. 2;

Fig. 6 is a plan view of a pilot keeper of a type which may be utilized with the latch;

Fig. 7 is a side View of a keeper having a resilient or flexible support, the supporting means being shown in cross section;

Fig. 8 is a view similar to Fig. 2 showing the bolt at the initiation of the draw-in operation; and

Fig. 9 is a representative force diagram showing the clamping force exerted by the latch throughout the drawin period.

Referring to the drawings:

The latch mechanism embodying the present invention y 2,128,596 Patented Dec. Z7, 1955 ICC has been shown, for convenience of illustration, in association with a refrigerator door 10 and a refrigerator cabinet 11. The refrigerator door 10 is of double wall panel construction having an outer wall 12 spaced from an inner wall 13 which is hinged to the refrigerator cabinet so that the door will close against the lefthand vertical panel 14 of the cabinet. The door 10 preferably is provided with a rubber-like seal or molding 15 about the periphery of its closing face so that the door opening of the cabinet will be sealed when the door 10 is closed.

The thickness of the door 10, including the space between the inner wall 13 and outer wall 12 and the size of the latch mechanism is such that the latch mechanism may readily be housed within the door. The latch mechanism is mounted within a frame which is generally U-shaped in cross section and which is disposed within the door 10 by means of a mounting bracket or strap 16 which is suitably secured to the wall panels of the door.

The U-shaped frame 20 is composed ofra rear wall 21 and side walls 22 and 23. The forward extremities of side walls 22 and 23 are provided with aligned notches 27 which are intended to receive the keeper when the door is closed, as will be more particularly described hereinafter. in the specific embodiment shown in the drawings, the forward extremities of the side walls 22 and 23 are slightly inset along the line indicated generally at 24 to form a more narrow or more closely spacedapart front portion and to accommodate outwardly struck lips 28 and 29 defining the top and bottom, respectively, ot' the notches 27. If desired, substantially the same dimensional results could be obtained without indenting the forward extremities of the side walls 22 and 23 by striking the lips 28 and 29 inwardly of the casing. The lips 28 and 29 form a bearing surface and guide for the keeper when it is inserted into the notches 27.

The rear wall 21 of the frame 2t) is provided with an aperture 30 having an outwardly struck flange 31 which is inserted within a registering opening 32 of the mounting bracket 16. Inserted through the openings 30 and 32 is a bushing 33 which is knurled as indicated at 34 for engagement with the flange 31. The bushing 33 forms a support for an actuating plunger 35.

Secured to the outer wall 12 is a handle mount indicated generally by the reference numeral 40, which pivotally supports a horizontally arranged handle grip 41 which is provided with an abutment 42 for engagement against the actuating plunger 35 when the handle grip 41 is pulled outwardly to open the door. The particular handle mechanism and plunger arrangement for actuating the latchhas been shown merely by way of completeness of illustration of the operation of the latch and does not of itself form a part of the invention. Many alternate forms of handle mechanisms or operation will be apparent to one skilled in the art and may be substituted, if desired, for that illustrated in the drawings without departing from the invention.

Pivotally supported within the frame 20 is a bolt 50 which is of a particular design and configuration in accordance with the invention for cooperation with the notches 27 and with the keeper. The form of the bolt Sti is best shown in Figs. 2, 3, 5 and 8 of the drawings. ln side View the bolt is generally C-shaped and includes an arcuate linger 51 which is the latching portion of the bolt, and reversely curved supporting and guiding portion 52. in commercial practice, it has been. found desirable to make the bolt initially in two side by side pieces 50a and Stlb which are welded together at the ends but which are spaced apart at 53 and 54, respectively, for mounting purposes. The widest spaced apart portion 53 is provided with apertures 55 through which are received a pivot pin 56 extending between the side walls 22 and 23. As a result, the bolt 50 may be freely pivoted about the pin 56, its pivoting movement being limited only by the engagement of the abutment 4S with the rear wall 21 as shown in Fig. 2 or by engagement of the spaced apart portion 54 with the rear wall as shown in Fig. 3. The spaced apart portion 53 of the bolt may be approximately as wide as the inner distance between frame side walls 22 and 23 as shown in the drawings to lend stability to the mounting and avoid sideplay or tilting of the bolt.

Mounted transversely of the bolt within the spaced apart portion 53 is a roller 57 which is in substantial alignment with the inner end of the actuating plunger 35. Accordingly, when the plunger is actuated inwardly as by means of the handle 4l, the bolt is moved in a counterclockwise direction about the pin 56.'

Received within the separated portion 54 of the bolt is one end of a spring guide 60 which is pivotally connected at that end to the bolt by means of the pivot pin 61 extending transversely therethrough and which is provided at its other end with an elongated longitudinal opening 62 in which is received a guide pin 63 extending between the opposite side walls of the frame. Extending between and abutting against a shoulder 64 on the guide and the pin 63 is a relatively stiff coil spring 65. As a result of the mounting of the spring guide 6i) and spring 65, an upward force is exerted on the pin 6l and hence the bolt 50 at all times. When the bolt is in the position shown in Fig. 2 o the drawings, the pivot pin 61 is to the left ot' a center line extending between pivot 56 and guide pin 63 and hence the thrust of the spring 65 urges the bolt into latching position, the clockwise movement of the bolt being limited only by engagement of the abutment 48 against the rear wall 2l ot the frame 20, as previously mentioned. Conversely, when the bolt S9 is in the position shown in Fig. 3, which occurs when the plunger 35 is thrust inwardly, the force of spring 65 is directed to the righthand side of the pivot pin 56 and hence the bolt 50 is retained in cocked or open position. ln other words, the form of the bolt 50 and the spring guide 6i) is such that an effective toggle is provided which will urge and retain the bolt 50 in either latching or unlatching position, depending upon whether the pin 6l falls to the right or left of the center line between the pivot 56 and guide pin 63.

A suitable keeper for use with the latch mechanism of the present invention is shown in Fig. 6 of the drawings and it comprises an elongated plate having a bifurcatcd end portion forming legs 71 and 72 which are bent at right angles to the plane of the plate 70 and which form a support at their outer end for a transverse post 73 on which are mounted roller means which. in the particular embodiment illustrated, comprises a plurality of side by side roller discs 74 of equal diameter. In some installations it may be preferred to make the endmost discs slightly larger in diameter than the center discs or, it preferred, a single elongated roller may be substituted for the plurality of discs. The plate 70 is provided with a series of lateral grooves and ridges as indicated at 75 and an elongated opening 76 whereby the keeper may be adjustably fastened to a supporting bracket Si) which is similarly transversely grooved as at 81 and has a tapped opening for receiving a holding screw 82. The supporting bracket Si) ot" course is mounted within the end wall 14 of the refrigerator cabinet and the keeper extends outwardly through a suitable aperture 33.

As previously'mentioned, the keeper is mounted in alignment with the notches 27 of the latch frame previously described. When the refrigerator door is moved to tripping position, the rst contact which takes place is between the outermost roller discs 74 and the lips lil 28 and 29 of the notches 27. Since the keeper is relatively rigid, the keeper will operate as a pilot by'engage= ment with the lips 28 and 29 to insure that the door is brought into accurate registry with the door opening. lt will be noted that the forward extremities of the lips 3S and 2? are flared downwardly and upwardly, respectively, to take care of any initial misalignment of the keeper and the notches.

As the roller discs 74 continue to enter the aligned notches 27 and with the bolt in retracted position, as shown in Fig. 3 of the drawings, the central roller discs 74 then engage against a face 58 which is formed on the outer end of the bolt portion 52 by outwardly bent anges S9. The face 58 is slightly arcuate and inclined rearwardly, as viewed in Fig. 3, so as to afford a desired camming action which assists in imparting pivoting movement to the boit 50 as a result of the engagement of the roller discs 74 with the face 58. By varying the inclination and curvature of the face 5S, the amount of thrust required to pivot the bolt 50 can be conveniently predetermined. The object is to so design the face 58 that, when the door is closed with a moderate or average thrust, the engagement of the roller discs 74 with the face 58 will cam the face 5S upwardly and rearwardly, causing the bolt to be pivoted sufficiently to move the spring guide 60 past the dead center position, as best shown in Fig. 8 of the drawings. When this position is reached, the tip of the linger portion 51 is behind the roller discs 74 and the spring 65 will be elective for urging the bolt into latching position. Thus, the draw-in of the door under the inuence of spring 65 will commence, and withdrawal of the keeper as by rebound of the door will be effectively prevented. The position of the linger portion 51 at this stage also shows why the keeper cannot be Withdrawn without full cooking of the latch when the door is opened. The arcuate finger portion 51 is anged as at 49 to provide a widened-out camming surface which operates on the rear of the roller discs 74 to draw in the door as the bolt is moved toward full latching position under the inuence of spring 65. i Y

By reason of the length of the linger portion 51, the curvature of the anged camming surface 49, the arrangement of the spring 65 and spring guide 60, and the offset pivot of the bolt on the pivot 56, the bolt can move into latching engagement with the keeper over a relatively long draw-in period and the distribution of the available draw-in force during the draw-in is greatly improved. The latch can readily be designed so that engagement of the linger with the keeper provides an initial draw-in force on the keeper throughout the greater portion of the draw-in period which is of a suciently high value to effectively draw in and clamp the door. tion it will be noted that the horizontal distance of the pivot 61 from pivot 56, and hence the effective leverage, increases as the bolt approaches closed position, and in iinal closed position the spring 65 and nger 51 are substantially in alignment. Y

The curvature of the face 49 is such that the distance of the face 49 from the pivot 56 increases inwardly from the tip or generally left to right as the bolt is viewed in the drawings. This causes the keeper to be cammed inwardly with a predetermined camming action as the bolt is pivoted to latching position and the linger portion S1 projects behind the keeper. This camming force is ren- 7 dered particularly effective by reason of the roller construction of the keeper which forms a rolling engagement with the face 49 as distinct from a conventional sliding or simple bearing action. As will be apparent, the force applied to the keeper by the bolt passes through the center line of the keeper, the bolt pivot, and midway between the guide slots. By proper selection of curvature of the face 49, it is possible to provide the desired level of draw-in force at any point of engagement and at the same time maintain the angle of the cam face relative to the line of force through the keeper within predeter- In this connec-l mined limits preferably not less than 73, i. e. a cam angle with the normal to that line of force of less than 17, so that it becomes virtually impossible to burst open the door merely by exerting a pulling force on the door. In other words, the latching of the door in fully closed position is accomplished by the predetermined camming action of the bolt which is present over a long draw-in period and is not dependent upon any necessary aligning of connecting links at fully latched position such as in conventional toggle type latches.

This feature of the refrigerator latch of the present invention is clearly illustrated in the exemplary diagram shown in Fig. 9 of the drawings in which the ordinate axis represents the clamping force in pounds exerted on the keeper by the latch, and the abscissas represent the distance of the keeper from closed position in thousandths of inches` The solid line curve of this diagram represents the performance of one actual embodiment of the latch of the present invention which is substantially identical with that shown in the drawings. it will be observed that the bolt is capable of engaging with the keeper while the keeper is still approximately one-half inch from closed position and that, when the door is approximately one-third inch from closed position, the clamping force has increased to over fifty pounds. Thereafter, for the remaining closed distances of the keeper, the clamping force remains above the fifty-pound level. l't may be desired in some installations to modify the curvature of the bolt to provide a peaking action, i. e. a rapid increase in draw-in force during the final latching movement of the bolt. Such an arrangement is indicated in dotted lines in the diagram of Fig. 9, the peak at the left hand extremity of the diagram being obtained by sacrificing some of the power previously utilized at the right hand extremity but still maintaining a substantial plateau at the center.

As a result of the operation of the latch as illustrated in the exemplary diagram of Fig. 9, the criticality of the mounting of the keeper and the latch is greatly reduced. Despite variations in the setting of the keeper, a strong clamping force will be exerted on the keeper and adequate drawing in of the door is insured.

in the event it is not desired to employ a pilot keeper of the type shown in Figs, 1 and 6 of the drawings, it may be preferred to mount the keeper as shown in Fig. 7 of the drawings. In this instance, the keeper 9i) is pivotally supported on a pin 9i which in turn is supported by a bracket 92. The keeper 90 has a rear plate 93 against which is abutted a spring 94 extending between the plate 93 and the rear plate 95 of the bracket 92. With this type of mounting, the keeper 90 is resiliently supported in horizontal position and if there is any misalignment of the apertures 27, this will be compensated for by pivoting movement of the keeper 96 rather than by any piloting action upon the door.

As many changes could be made in the above construction and many apparently widely different embodiments of this invention could be made without departing from the scope thereof, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

It is also to be understood that the language in the following claims is intended to cover all of the generic and specic features of the invention herein described and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.

We claim as our invention:

l. A latch mechanism adapted to engage a keeper, comprising a frame having a keeper-receiving guideway therein, a C-shaped bolt having a latching finger portion and a positioning finger portion, a pivot for supporting the bolt in the frame for limited pivoting movement in either direction between a cocked and a latching position, said pivot being offset from the center of said bolt towards said positioning finger portion and being in alignment with the longitudinal centerline of said guideway, a spring engaging the bolt at a point spaced from the pivot and towards said latching linger portion to urge said bolt in either direction, means on said positioning finger portion to engage the keeper when the bolt is in cocked position, the point of said engagement being above the longitudinal centerline of said guideway to initiate movement of the bolt to latching position, and an inwardly facing cam surface on said latching iinger portion for engagement behind the keeper as the bolt is pivoted to latching position in which position the point of engagement of the bolt and keeper is in alignment with the longitudinal centerline of the guideway and the bolt pivot.

2. A latch mechanism adapted to engage a keeper comprising a frame having a keeper receiving guideway therein, said guideway having a C-shaped bolt having a latching finger portion and a positioning finger portion, a pivot supporting said bolt in the frame for limited pivoting movement between a cocked position and a latched position, said pivot being in alignment with the longitudinal centerline of said guideway, a surface on said positioning finger portion adapted to engage the keeper at a point above the longitudinal centerline'of said guideway when the bolt is in cocked position, means on said latching finger portion to engage the keeper when the bolt is in latched position, an actuating toggle for said bolt comprising a spring and spring guide member, said guide member being pivotally attached at one end to the bolt at a pointbetween Said pivot and said latching finger portion and slidably and pivotally attached to said frame at a point below said bolt, said spring being disposed when the bolt is in the cocked position such that the force of the spring is directed forwardly of said bolt pivot to maintain the bolt in the cocked position, said spring being disposed when the bolt is in the latched position such that the face of the spring is directed rearwardly of the point of engagement of said bolt and keeper to maintain the bolt in a latched position wherein said point of engagement is in alignment with the longitudinal centerline of said guideway and the bolt pivot, and roller means on the keeper comprising a plurality of spaced apart rollers for engagement with said guideway and rollers intermediate said spaced apart rollers for engagement with said latching `linger portion of the bolt.

References Cited inthe file of this patent UNITED STATES PATENTS 889,365 Gray June 2, 1908 966,926 Knapp Aug. 9, 1910 1,269,467 Leonard et al June 11, 1918 1,275,954 McGowan Aug. 13, 1918 2,129,926 Geske et al Sept. 13, 1938 

